Shape memory alloy elements are distinguished in that they may be used as actuators with high energy density.
Valves are known in which one or more actuating elements cooperate with shape memory alloy elements in the form of a wire, as is described in DE 102 33 601, for example.
Foils made from shape memory alloys are also known. In this case, only a very small travel for controlling the stroke of a valve is available in valves, and only low pressures can be controlled.
Moreover, known valves based on the shape memory alloy principle for the actuator are NO designs (i.e. “normally open”) in many cases. As a rule, industrial applications require NC valves (i.e. “normally closed”) which are closed in the state of rest and will not open until they are acted upon by an electrical current.